here's the deal i have an 88 vert with many new parts, new fuel pump, new injectors, spark plugs, plug wires, radiator, clutch, master and slave cylinder and a fresh rebuild on the stock n/a motor, on startup the car will rev to 2000 then slowly idle down like it should on warmup but it doesnt stop going down it will get to about 200 and then die, if i keep my foot on the pedal i can keep it running , i have checked my bac valve and aws as well as verified timing cannot find any vacuum leaks , when the rebuild was done i replaced all vacuum lines with new silicone hoses, also when i try to adjust idle nothing ever changes i can adjust the idle screw on the throttle body but nothing changes, i even checked throttle cable adjust because i put a new cable on as the old one got broken on motor removal i just cannot figure out how to make this idle any help would be appreciated

 

New rebuilds sometimes need to be run in for a little while before they will idle at low rpms. Use the cruise control cable tension to pull the throttle open and drive the car around with a higher idle like around 1500 rpms

 

check and make sure your throttle cable isnt loose, if it is try to tighten it up , that can cause the car not to hold idlle, my car has had that problem for awhile, i think my cable may even be stretched i have no idea

 

rebuilds hate idle, they need to run alot just go drive it all day it will love it just dont drive hard
they need to build comression

 

for rebuild engines, you need to set your idle high... id say around 1200-1400k for the first 500 miles or so....then you can try adjusting it down after. use the adjusting screw to raise the idle and or the bac if you still have it

 

My new engine has just been running for the last couple weeks and I can't get the idle over about 800. Idle screw is all the way out. How do you adjust the bac?

 

OP, is your TPS adjusted within spec?

 

to answer all these questions i know the car should be set to idel high for the break in but i cant get it to idle anywhere high or low , the car didnt come with cruise control so there is no cable to tension on that unless i can wire it or something but would definitely like to not be rigging things, as far as the tps i know its in the fsm but for some reason i couldnt find it last night but i tried checking it based on my memory it should be set to about 1000 when i checked it my meter reads 1004 which is pretty close but let me know if i am wrong. i would like to know what else can effect idle it just seems that i have either check or replaced almost everything on this car and still wont idle anywhere i would just drive around but once it dies when i have to come to a stop i'll be sitting there waiting to restart the car i did put a fuel switch on so i could at least restart but it still takes a lil bit.

 

ok so i took it for a drive and found that when i shift if i take my foot off the accelerator the car will die almost instantly but if i rev it up in my driveway it will slowly idle down until it dies dont know why the difference between moving or not but that is what its doing after driving it for a little while and restarting in my garage it does now seem to idle itself around 800 but it still wont let me adjust it in any direction.